¥Thick mucosa covering the anterior lacrimal

¥Agger nasi anterior ethmoid cells (8% of cases), uncapping the cell with the laser allows access to the bone that lies medial to the lacrimal sac.

¥Thick bone

3.3.5 Post-Operative Care After ELDCR

¥Laser DCRs can be performed as an outpatient procedure under local anaesthesia.

¥Patients are instructed to douche their nose with saline.

¥Antibiotics are not routinely prescribed, except in cases of infection.

¥Patients are instructed to avoid heavy lifting, bending or straining, or blowing their noses for some days.

¥Slough covers the Þstula within 48 h and this clears up within 10 days.

¥A Þrst review is recommended after 7 days to inspect the site of the rhinostomy using a nasendoscope and to remove crusts or granulations if necessary.

¥The stents are removed transnasally 6 weeks postoperatively by cutting the loop between the cannaliculi.

¥After 3 months the Þstula cannot always be detected as a distinct opening, and the operation site may show a slight dimple, or may appear completely normal.

3.3.6 Results of ELDCR

Most failures occur in the Þrst 18 months due to stenosis at the rhinostomy site although late stenosis can occur up to 3 years after surgery.

The literature reports success rates for the various lasers of around 60Ð80% [11, 38, 46, 49, 54, 55, 68, 95] with the Holium:YAG laser perhaps having a better success rate with up to 99% in one series [14].

In the prospective comparative study of Moore et al. the results after endonasal conventional DCR were better than those using a holmium laser (but not signiÞcantly); however, there was a substantial difference in the size of the bone windows (10 × 10 mm vs. 6 × 6 mm) [56].

In a recent paper by Bakri et al. the authors came to the conclusion that the results of laser assisted DCR are poorer than those of external or conventional endonasal DCR [4].

ArecentprospectiverandomisedtrialbyAjalloueyan et al. 2007 demonstrated comparable success rates of external DCR and ELDCR (92.4% vs. 94.2%) in 244 eyes [3]. There was less morbidity and shorter operative time in the laser group. The authors used the diode laser creating a 1 × 1 cm wide opening.

Irrespective of the type of laser used the crucial operative parameter is always the creation of a large opening between the lumen of the lacrimal sac and the nasal cavity, because there is a pronounced shrinking tendency.

3.3.7Post-Operative Complications After ELDCR

In the majority of patients, there are very few postoperative complications, and the procedure is associated with very low morbidity:

¥SigniÞcant haemorrhage is rare in Laser DCR and only occasionally is nasal packing necessary.

¥Rarely, granulations form at the site of the Þstula. The most likely cause of granulation formation is a low-grade infection or a foreign body reaction to the stent if it rubs the rhinostomy site. Stent removal usually results in a satisfactory resolution. Antibiotic nasal and eye drops may help reduce the incidence of granulations.

¥Synechia usually form between the lateral surface of the middle turbinate and the medial surface of the lateral wall of the nose and may obstruct the rhinostomy, resulting in failure of the procedure. The damage may result from instrumentation or from the spread of laser thermal energy to surrounding non-target structures. If the synechae are symptomatic then revision surgery may be required.

¥An excessively tight stent may cut through the canaliculus as well as the skin in between them. The raw surfaces may heal with a web, which buries the stent. This usually results in scarring and may disrupt the lacrimal drainage pump system. A migrated stent can be retrieved from the nose by cutting one of the tubes that form the loop before the sleeve or